This invention relates generally to gasification systems, and more specifically to methods and systems for injecting feed into a gasifier.
At least some known gasifiers convert a mixture of fuel, air or oxygen, liquid water and/or steam, and/or slag into an output of partially oxidized gas, sometimes referred to as “syngas.” In an integrated gasification combined-cycle (IGCC) power generation system, syngas is supplied to the combustor of a gas turbine engine, which powers a generator that supplies electrical power to a power grid. Exhaust from the gas turbine engines may be supplied to a heat recovery steam generator that generates steam for driving a steam turbine. Power generated by the steam turbine also drives an electrical generator that provides electrical power to the power grid.
The fuel, air or oxygen, liquid water and/or steam, and/or slag additive(s) are injected into the gasifier from separate sources through a feed injector that couples the feed sources to a feed nozzle. The feed sources traverse the feed injector separately and are mixed together in a reaction zone downstream from the nozzle. For the reaction to complete in the short time the mixture is in residence in the reaction zone, intimate mixing of the feed components is essential. Such mixing is facilitated by disposing or atomizing, the feed components in a fine spray. Generally, a finer spray, or smaller droplet size, of the feed components yields a more complete combustion of the feed components. At least some know gasification feed injectors reduce one or more flow paths that the feed components flow through to achieve a smaller droplet size. However, such feed injector flow paths are constrained by the size of the feed component particles and a reduction of droplet size may be limited thereby.